Carton folding machine



1963 w. J. KREIMENDAHL 3,115,073

CARTON FOLDING MACHINE 6 Sheets-Sheet 1 Filed April 18, 1962 INVENTOR. WILLIAM J. KREIMENDAHL PATENT AGENT 1963 w. J. KREIMENDAHL 3,115,073

CARTON FOLDING MACHINE Filed April 18, 1962 6 Sheets-Sheet 2 INVENTOR.

WILLIAM J. KREIMENDAHL wwaww PATENT AGENT 1963 w. J. KREIMENDAHL I 3,115,073

CARTON FOLDING MACHINE 6 Sheets- Sheet 5 Filed April 18, 1962 INVENTOR. WILLIAM J. KREIMENDAHL BY Mam). 707M PATENT AGENT c- 1963 w. J. KREIMENDAHL 3,115,073

CARTON FOLDING MACHINE Filed April 18, 1962 6 Sheets-Sheet 4 l INVENTOR. WILLIAM J. KREIMENDAHL PATENT AGENT w. J. KREIMENDAHL 3,115,073

CARTON FOLDING MACHINE Dec. 24, 1963 6 Sheets-Sheet 5 Filed April 18, 1962 FIG. 20

INVENTOR. WILLIAM J. KREIMENDAHL PATENT AGENT Dec. 24, 1963 w, J. KREIMENDAHL 3,115,073

CARTON FOLDING MACHINE Filed April 18, 1962 6 Sheets-Sheet e FIG. l9 INVENTOR.

WILIIEYI AM J KREIMENDAHL PATENT AGENT United States Patent 3,115,073 CARTON FOLDING MACHINE William J. Kreimendahl, Westfield, Mass, assignor to West Virginia Pulp and Paper Company, New York, N.Y., a corporation of Delaware Filed Apr. 18, 1962, Ser. No. 188,324 4 Claims. (Cl. 93--51) This invention relates generally to improvements in carton folding machines and, particularly, to improvements in a carton folding machine of the die and plunger type in which the carton is adhesively held in the erected form.

Methods of folding cartons vary from simple manual setup means to complex automatic machinery that begins with a pre-cut blank and performs a series of operations on the blank until a completely erected carton is formed. Automatic carton folding methods have developed numerous types of carton folding machines. The present invention is primarily concerned with improvements in the types of carton folding machines employing a reciprocating plunger that pushes the blank down through a die, forming the carton about the plunger during the downward stroke.

A great number of plunger and die carton folding machines have been developed to erect tab-slot cartons. As the name implies, tab-slot cartons are held in erected form by various combinations of tabs that are received by and held in suitable slots usually cut in the side panels of the cartons. Tab-slot carton folding machines have advantageous features, such as high production rates. However, tab-slot cartons usually require an outer yvrap or inner wrap to make the cartons liquid tight. Tab-slot frozen food cartons, in which the foodstuffs have considerable amounts of liquid must contain a liquid tight wrap to prevent leakage, especially prior to freezing. The outer wrap or inner wrap, whichever the case may be, considerably increases the amount of packaging paper required, such as waxed paper which is reflected in the overall cost of each carton.

The tab-slot carton folding machines use relatively complex forming dies for tucking the tabs in the slots and, in some cases, the stroke of the plunger is increased so that the various tucking operations can occur during the downward stroke of the plunger. The prior art teaches the usage of two plunger-die machines in series with the first plunger-die machine setting up tab-slot cartons and the second plunger-die machine setting up the inner wraps, thus adding greatly to the expense and complexity of the overall carton folding operation.

Tab-slot cartons, in the absence of inner wraps or outer wraps, have a liquid level that cannot extend above the lower part of the slot cut in the side panels of the cartons. As a result, the amount of cooking fats, vegetable juices, and the like that can be packaged along with solid foodstuffs is limited to that of the height of the lower part of the slot. Some tab-slot cartons contained slots located on the upper edge of the side panels, such as the carton disclosed in the Patent 2,909,105 to M. J. Lawrence. The Lawrence cartons overcome the low liquid levels that are an inherent disadvantage of tab-slot cartons having slots lower on the side panels, but unfortunately is not completely liquid tight. The slot, without an overwrap, will permit a leakage of fluid contents if and when the carton is placed in any position other than horizontal.

Recent developments in completely liquid tight cartons are similar to the carton shown in the Patent 3,010,373 to R. W. E. Mosse. The Mosse cart-on folding machine sets up a carton adhesively held erect and contains no slots through which the fluid contents can escape.

Like Mosse, the applicants carton folding machine sets up a carton adhesively held erect. Unlike Mosse, the applicants carton folding machine begins with a glueless blank, and applies glue during carton set-up.

Methods in which glue is pre-applied to the carton blanks, then hardened prior to set-up require an additional stepof re-activating the glue by either rewettin-g or reheatlng the glued surfaces during or just prior to carton set-up. As a result, in the case of the glues activated by heat, the reheating is wasteful because the glue is heated to the liquid state during the application to the blank. Regardless of the type of glue, an additional step is imposed during carton set-up which results in an overall increase 1n carton set-up time.

Carton folding machine's designed according to the apphcants invention have overcome the disadvantages of the prior tab-slot and glued carton folding machines. The machine produces a carton having a high liquid level without using an inner or outer wrap, and is considerably simpler than the tab-slot carton machines. In addition, the reheat or rewet step used in the majority of the prior art carton machines forming glued cartons has been eliminated.

Briefly, the applicants carton folding machine operation begins with non-glued blank that is fed into position over the die. The plunger forces the carton blank down through the various parts of the die during which the glue is applied to the carton. The glue sets quickly during the stroke of the plunger through the die, and is able to hold the oarton in erected form by the completion of the stroke. There is an overall decrease in set-up time as compared to the earlier glued cartons, and a drastic simplification of carton folding machine as compared to the tab-slot cartons.

The major advantage is the ability of the carton folding machine to begin with a blank having no pre applied glue and thenbe able to apply glue during the forming operations in such a manner that the carton is completely erected by the completion of the downward stroke of the plunger.

In addition, because of the novel features of the carton folding machine, the web corners of the cartons are folded inside of the carton side panels without the use of special folding fingers which decreases the length of the stroke of the plunger as compared to machines needing special folding fingers, and thus reduces the time required for each carton set-up.

By folding the web corners inside of the side panels, the overall appearance of the carton is greatly enhanced and is prevented from being involved in a separation between the web corners and the side panels during packaging, shipping, and various other forms of handling.

Not only is the :step of reheating or rewetting pre-applied glue eliminated, but also the amount of glue necessary to form a sufiicient bond is carefully controlled and thus greatly reduced by the carton folding machine.

The glue application is further improved by a novel use of a car-ton forming portion of the die which cooperates in a novel manner with glue applicating means to hold the adhering portions of the carton together during the glue hardening as will become obvious in the following discussion.

Additional advantages of this invention will hereinafter more fully appear in connection with the detailed description of the drawings in which:

FIG. 1 is a perspective view of the forming die of the carton folding machine with certain parts removed to show novel features according to the invention.

FIG. 2 is a carton blank of the type set up by the carton folding machinery.

FIG. 3 is the oarton shown in FIG. 2 partially folded.

FIG. 4 is the carton shown in FIG. 3 during an additional fold.

FIG. is the carton shown in FIG. 4 completely folded.

FIG. 6 is a perspective view illustrating the forming die of the carton folding machine with additional parts removed to show still other novel features according to the invention.

FIG. 7 is an elevational sectional View of the carton folding machine showing the operation of the adhesive applicators of the carton folding machine during carton set-up.

FIG. 8 is an elevational sectional view similar to FIG. 7 in which the adhesive applicators are in another phase of operation during carton set-up.

FIG. 9 is an enlarged sectional view of a portion of the adhesive assembly of the carton folding machine taken along line 99 of FIG. 7.

FIG. 10 is an enlarged sectional view taken along line 1010 of FIG. 9 showing a portion of the adhesive assembly during a particular phase of carton set-up.

FIG. 11 is an enlarged sectional view similar to FIG. 10 showing a portion of the adhesive assembly in another phase of carton set-up.

FIG. 12 is an enlarged sectional view of another embodiment of the portion of the adhesive assembly shown in FIG. 11.

FIG. 13 is another enlarged sectional view of the por tion of the adhesive assembly shown in FIG. 12.

FIG. 14 is an enlarged fragmentary elevational view of a portion of the forming die of the carton folding machine during a particular phase of carton set-up.

FIG. 15 is an enlarged fragmentary elevational view similar to FIG. 14 in another phase of carton set-up.

FIG. 16 is an enlarged fragmentary elevational view similar to FIG. 15 showing yet another phase of carton set-up.

FIG. 17 is an elevational sectional view of the carton folding machine taken along line 1717 of FIG. 8.

FIG. 18 is an elevational sectional view similar to FIG. 17 showing another phase of carton set-up.

FIG. 19 is an elevational sectional view taken along line 1919 of FIG. 18 showing certain features of the carton folding machine.

FIG. 20 is a partial view of a corner of the plunger.

Referring to FIG. 1, the forming die is positioned by a substantially horizontal die table 10 that is carried by the pair of die table supports 11. The die table supports 11 are attached to framing members (not shown) that position the die table 10 underneath a reciprocating plunger 12 (see FIGS. 7 and 8) so that the plunger 12 passes through the forming die to erect the cartons as will become obvious in the following detailed description. The upper surface of the die table 10 is relatively smooth and contains six carton positioning blocks 13. It is to be understood that two of the carton positioning blocks 13 have been removed along with a portion of the die table 19 in order to show the parts of the forming die.

An embodiment of a carton erected by the carton folding machine is shown in FIGS. 2 through 5. Referring to FIG. 2, the carton blank contains side panels 14- and end panels 15 foldably attached to a bottom panel 16. The carton blank contains a top panel 17 and three overlapping panels 18 that are foldably attached around three sides of the top panel 17. The remaining side of the top panel 17 is foldably attached to one of the side panels 14. The carton contains four similar web corners 19 foldably attached to the side panels 14 and the end panels 15 by score lines 26 and 21, respectively. The web corners are equally divided into triangular segments 22 and 23 by the diagonal score lines 24. Notice that the triangular segments 23 contain a cutout 25 on the free edge. The carton features will be further explained herein as required for an understanding of the operation of the carton folding machine.

The carton blank is fed onto the die table 16 and positioned by the carton positioning blocks 13 so that the bottom panel 16 is over the forming die and in the path of the reciprocating plunger 12. The plunger 12 contacts the blank with a face that conforms generally to the bottom panel 16 of the carton. The forming die cooperates with the plunger during its pass therethrough to perform a series of folding operations on the carton blank. For clarity, the forming die has been divided according to folding operation into a first or upper portion, and a second or lower portion. The first portion begins carton erection by folding the carton side panels 14 upwardly about the bottom panel 16. This phase of erection is shown in FIG. 3. The second portion completes carton erection by folding the end panels 15 upwardly about the bottom panel 16 While folding web corners 19 inside thereof. The carton is shown during this phase of erection in FIG. 4, and in completely erected form in FIG. 5.

Referring to FIGS. 1 and 6, the first or upper portion of the forming die is defined by a first pair of forming plates 26, and a pair of side walls 27. The first pair of forming plates 26 are attached by suitable fasteners 23 to the die table 10 so that flanged portions are substantially flush with the upper surface of the die table 10 and so that portions extend downwardly thus forming opposing side walls substantially perpendicular to the upper surface of the die table 10. The pair of parallel side walls 27 extend downwardly from the lower surface of the die table forming the remaining walls of the forming die and are attached to the die table by suitable fasteners 29. It is to be understood that one of the side walls 27 has been removed from FIGS. 1 and 6 in order to show the various components located in the second or lower portion of the forming die. The side walls 27 are spaced apart a distance substantially equal to the total length of the carton blank; i.e., the sum of the widths of the end panels 15 and the length of the bottom panel 16. The portions of the first pair of forming plates 26 that extend downwardly into the forming die are spaced apart a distance substantially equal to the width of the bottom panel 16. The plunger 12 contacts the bottom panel 16 of the blank with a face that conforms generally to the bottom panel 16 and pushes the blank downwardly into the forming die. The side panels 14 are folded upwardly about the plunger 12 into a position substantially perpendicular to the bottom panel 16 by the first pair of forming plates 26. The end panels 15 are not folded and lie in the same plane as the bottom panel 16 and the web corners 19 are coplanar with the side panels 14. The carton is partially erected as shown in FIG. 3.

Immediately following the completion of the first folding operation, the plunger 12 pushes the partially erected carton past glue applying heads 30. The forming die contains two pairs of glue applying heads 30 that extend through cutouts provided in the first pair of forming plates 26. The glue applying heads 39 are equally spaced from the side Walls 27 and are positioned in the part of the forming die through which the web corners 19 pass. The glue applying heads 31 extrude glue onto the triangular segments 22 of each web corner 19 as indicated by the shaded areas 31 of FIGS. 3 and 4. Glue is fed to the glue applying heads 30 from a suitable glue supply 32. The glue supply 32 is preferably a hot melt unit and can be a commercial unit containing means for liquifying the hot melt which is commercially obtainable in solid ribbon form, a reservoir for retaining a supply of liquid hot melt, and means for feeding measured amounts of the liquid hot melt from the reservoir to the glue applying heads 30. Two glue supplies 32 are positioned underneath the die table 10, one behind each of the first pair of forming plates 26. One glue supply feeds two glue applying heads.

Referring generally to FIGS. 1 and 9, and particularly to FIG. 9, the glue applying heads 30 are formed from the end portions of two extrusion bars 33. The center portion of the extrusion bars 33 are connected to heating units 34 and to the glue supply 32. The heating units 34 hold the hot melt temperature above solidification during the transfer from the reservoir to the glue applying heads 30. The glue flows from the glue supply 32 to the liquid hot melt channel 35. The glue flows in two directions from the hot melt channel 35 along the hot melts channels 36 to the hot melt channels 37. A valve rod 38 passes through axially aligned holes drilled in the glue applying heads 30. The valve rod 38 protrudes beyond both ends of the extrusion bar 33 and is capped on one end by a retainer ring 39, and on the other end by a sleeve valve link 40 thus preventing all but rotational movement of the valve rod 38. The end portions of the valve rod 38 contain holes 41 that, in FIG. 11, are aligned with the hot melt channels 37. As a result, the liquid hot melt flows from the hot melt channels 37 through the holes 41 and through a pair of extrusion holes 42 drilled in a wall of the glue applying heads 30. With the valve rod 38 in this position, the liquid hot melt is extruded onto the triangular segments 22 of the web corners 19 of the carton. The area of the triangular segment covered during the extrusion is not limited to the shaded area 31 as indicated in FIG. 3, but may be varied in length and width to suit the requirements of various types of cartons.

FIG. is a view of one of the glue applying heads 30 showing the valve rod 38 after rotation from the position as shown in FIG. 11 so that the hole 41 is no longer aligned with the liquid hot melt channel 37 and the extrusion holes 42. The liquid hot melt cannot be extruded while the valve rod 38 is held in this position. By cycling the valve rod 38 between the two positions, the extrusion of liquid hot melt can be timed to occur during the passage of a predetermined portion of the carton. The wall of the glue applying heads 30 containing the extrusion holes 42 should be approximately 0.060" thick. Thicker walls have a tendency to drool liquid hot melt after the valve rod 38 has been rotated to the closed position of FIG. 10. The extrusion holes 42 should be in the order of 0.050 in diameter. Larger diameter holes contain excess liquid hot melt that tend to drool.

FIG. 12 is a View of another embodiment of one of the glue applying heads 30 in which thin strips of bronze 43 are wrapped around the surfaces of the glue applying heads 30. The bronze strips cover the hot melt channels 44 drilled in the walls of the glue applying heads 30. In this particular embodiment, the extrusion holes 42 are drilled in the bronze strips 43 and the hot melt channels 44 in the extrusion head are drilled to a size substantially equal to the size of the holes 41 drilled through the valve rods 38. The bronze strips 43 are approximately 0.005" thick and are positioned on the surface of the glue applying heads 30 by the fasteners 45.

FIG. 13 is a partial fragmentary view similar to FIG. 9 in which the embodiment of the glue applying heads 30 of FIG. 12 is represented. The bronze strips 43 extend partially across the face of the glue applying heads 30. Each bronze strip 43 contains one extrusion hole 42 as compared to two extrusion holes 42 for the embodiment of the glue applying heads 39 shown in FIGS. 9, 10 and 11. The glue pattern applied by the single extrusion hole 42 of FIGS. 12 and 13 is narrower than the glue pattern applied by the two extrusion holes 42 of FIGS. 9, 10 and 11. The difference in the extrusion holes 42 of the two embodiments of the glue applying heads 30 is illustrative of a means for changing the glue pattern to suit dilferent types of cartons. It is to be understood that either embodiment could have two extrusion holes 42 or one extrusion hole 42. As was the case of the glue applying heads 30 of FIGS. 9, 10 and 11, the glue applying heads 30 of FIGS. 12 and 13 should have a thin wall of approximately 0.060" thick and the diameter of the extrusion holes 42 should be in the order of 0.050." An activating mechanism for the embodiments of the glue applying heads 30 that cycles the valve rod 38 between the two positions as indicated in FIGS. 10 and 11 is shown in FIGS. 1, 7 and 8.

The opposite end of the sleeve valve link 40 is pivotably attached to a drag link 46. The opposite end of the drag link 46 is pivotably attached to one end of a cam follower link 47. The other end of the cam follower link 47 carries a cam follower 48. The intermediate portion of the cam follower link 47 is pivotably attached to the pin 49 which is attached to the nearest cam shaft bearing housing 50. Referring in particular to FIG. 6, the carton folding machine contains four cam shaft bearing housings 50, two behind each of the first pair of forming plates 26.

A cam shaft 51 is received by bearings 52 that are carried by the cam shaft bearing housings 50. A second cam shaft 53 is carried by bearings 52 in the remaining cam shaft bearing housings 50. The cam shafts 51 and 53 are axially parallel, and are driven at a constant and equal rotative speed in opposite directions. Cam shaft 51 is driven clockwise as viewed in FIGS. 1, 6, 7 and 8 and cam shaft 53 is driven counterclockwise as viewed in FIGS. 1 and 6. Although not specially called for inthe drawings, any means that drives the cam shafts 51 and 53 in the directions indicated can be used. The drive means must rotate the cam shafts 51 and 53 one complete revolution during the time required for the plunger 12 to com plete one cycle. The plunger 12 cycle is one stroke downwardly through the forming die (forming stroke) andone stroke upwardly through the forming die (return strokes). One glue applicator czun 54 is mounted'on each of thecam shafts 51 and 53 so that the cam surfaces contact the cam followers 48. It is to be understood the separate and identical mechanisms operate the glue applying heads 30, each mechanism being activated simultaneously according to the following description.

In FIG. 7, carton setup has begun with the plunger 12 traveling downwardly through the first or upper part of the forming die in the direction indicated by the arrow. The cam follower 48, in this phase of carton setup, is riding on the raised portion of the glue applicator cam 54. Notice that the carton has not reached the glue applying heads 30. In FIG. 8, the adhesive applicator cam 54 has been rotated in the direction indicated by the cam shaft 51 so that the cam follower 48 is riding on the recessed portion causing a clockwise rotation of the cam follower link 47 as compared with the same link as shown in FIG. 7. The clockwise rotation of the cam follower link 47 rotates the sleeve valve link 40 and the valve rod 38 counterclockwise because of the pushing action exerted on the lower end of the sleeve valve link 40 by the drag link 46. The plunger 12, traveling downwardly through the first or upper part of the forming die in the direction indicated by the arrow, has moved the side panels 14 of the carton partially past the glue applying heads 30 which are applying liquid hot melt to the shaded areas 32 of the triangular segments 22 of the web corners 19 as shown in FIG. 3. The transfer of liquid hot melt occurs when the cam follower 48 is riding on the recessed portion of the glue applicator cam 54, and does not occur when the cam follower 48 is riding on the raised portion of the glue applicator cam 54. The length'of the recessed portion of the adhesive applicator cam 54 is proportional to the length of the area of the liquid hot melt transferred to the carton. The length of the recessed portion of the glue applicator cam 54 can be changed to vary the length of the glued area as required for other types of cartons. It is to be understood that in FIG. 7 the valve rod 38 is positioned as shown in FIG. 10, and that in FIG. 8 the valve rod 38 is positioned as shown in FIG. 11. A tension spring 55 holds the cam follower 48 firmly against the surface of the glue applicator cams 54.

Experience has shown that the transfer of glue to the carton is greatly enhanced if the natural resiliency of the board is employed to bow the web corners 19 against the glue applying heads 30. The lower portion of the web corners 19 travel downwardly into the second or lower portion of the forming die during glue application. The second or lower portion of the forming die would prevent bowing unless designed to be moved away from the plunger 12 during the application of glue. A pair of movable die plates 56 form two opposing walls of the lower or second portion of the forming die underneath the glue applying heads 30 and are withdrawn from the plunger 12 by suitable mechanisms during the glue application phase of the carton setup operations.

The pair of movable die plates 56 are clearly indicated in FIGS. 6, 14, 15, and 16. In FIG. 6, the glue applying assemblies of FIG. 1 have been removed to show the parts of the carton forming machine related to the movable die plates 56. Two parallel bars 57 are attached by suitable fasteners 58 to the back surfaces of each movable die plate 56 in a substantially vertical position near the extreme ends thereof. A U-shaped link 59 has two uppermost ends pivotably attached to the facing sides of the top portions of the parallel bars 57. Axially aligned bosses 60 are permanently afiixed to the outside faces of the lower part of the U-shaped links 59. Each boss 60 is pivotably attached to the upper portion of the nearest cam shaft bearing housing 59. The lower portions of each parallel bar 57 is pivotably attached to a connecting link 61. The opposite end of the connecting link 61 is pivotably attached to the nearest cam shaft bearing housing 50.

A die plate cam 62 is attached to each of the cam shafts 51 and 53. The die plate cams 62 contain identical surfaces and transmit identical action to cam followers 63. Each cam follower 63 is connected by a rod 64 to the lower portion of one of the U-shaped links 59. It is to be understood that separate and identical mechanisms operate each movable die plate 56.

Now that the overall physical deployment of the mechanisms activating the movable die plates 56 has been described, refer to FIG. 14 in connection with a description of the operating characteristics. The plunger 12 has moved downwardly into the forming die in the direction indicated by the arrow and has erected the carton as shown in FIG. 3. The lower portions of the side panels 14 and the web corners 19 of the carton extend into the lower or second portion of the forming die, and the web corners 19 are receiving glue from the glue applying heads 30. The movable die plates 56 are removed from the plunger 12 and do not contact the side panels 14 and the web corners 19 of the carton. The web corners 19 are being held by the natural resiliency of the carton board against the glue applying heads 30. The U-shaped link 59, as explained in connection with FIG. 6, is pivot ably located on the cam shaft bearing housings 50. Only a fraction of the die plate cam 62 is shown in FIG. 14 so that the cooperation of the mechanisms operating the movable die plates 56 can be clearly seen. The die plate cam 62 is rotating in the direction indicated by the arrow. The cam follower 63 is riding on the raised portion of the die plate cam 62. While on the raised portion, the U-shaped link 59 is held in a clockwise position by the cam follower 63. The top of the U-shaped link 59 is held away from the plunger 12 and, through the pivotable connection, holds the upper portion of the movable die plate 56 away from the plunger 12. The connecting link 61 is pivoted about its end connections causing a removal of the bottom portion of the movable die plate 56. The distance between the end connections of the connecting link 61 is equal to the distance separating the pivot connections between the parallel bars 57 and the U- shaped link 59, and the pivot connection between the bosses 69 and the cam shaft bearing housings 50, which brings about a parallel movement of the movable die plate 56. The parallel movement keeps the movable die plates 56 horizontal throughout the movement. A tension spring 65 has one end connected to the cam follower rod 64 and the other end connected to a suitable frame member (not shown) such that the tension in the spring 65 holds the cam follower 63 firmly against the surface of the die plate cam 62.

As the plunger 12 continues downwardly through the forming die, the side panels 14 pass beyond the glue applying heads 30 and completely into the lower or second portion of the forming die. Referring to FIGS. 1 and 6, the second or lower portion of the forming die is defined by a second pair of forming plates 66, and the movable die plates 56. The second pair of forming plates 66 are attached to the lower end of the side walls 27 and extend inwardly therefrom. The second pair of forming plates 66 have inner reaches that are gently curved until portions extend downwardly forming opposing side walls substantially perpendicular to the surface of the die table 10. The curved portions cooperate with the plunger 12 to erect the end panels 15 while folding the web corners 19 inside of the end panels 15 such that the triangular segments 22 and 23 are overlapped with the glue areas 31 deployed over the cutouts 25.

A better understanding of the folding operation performed in the lower or second portion of the forming die by the second pair of forming plates 66 can be obtained by referring to FIGS. 17 and 18. In FIG. 17, the plunger 12 is traveling downwardly through the forming die as indicated by the arrow. It is to be understood that one of the first pair of forming plates 26 and one of the movable die plates 56 has been removed from FIGS. 17 and 18 so that the folding action of the second pair of forming plates 66 can be clearly shown. In the position shown, the plunger 12 has traveled to a point just prior to the beginning of the folding operation by the second pair of forming plates 66. The side panels 14 of the carton have been folded as shown in FIG. 3. The glue has been applied in the shaded areas 31 by the glue applying heads 30 as described previously. In FIG. 18, the plunger 12 has traveled further into the die as compared with FIG. 17 and has cooperated with the second pair of forming plates 66 to partially fold the end panels 15 upwardly as shown in FIG. 4. The triangular segments 22 of the web corners 19 have been folded inwardly toward the plunger 12 with the glued areas 31 facing toward the end panels 15. The triangular segments 22 and 23 of the web corners 19 have been folded into overlapping relation by the second pair of forming plates 66 as the plunger '12 pushed the carton thereby. Upon slightly further travel of the plunger 12, the glue areas 31 on the triangular segments 22 presses against the surface of the triangular segment 22 land through the cutouts 25 against the inner surface of the end panels 15.

Notice from the drawings, particularly FIG. 20, which is a partial view of a typical corner of the plunger 12, that each corner of the plunger 12 contains a protrusion 67 that is aligned with the cutout 25 on the triangular segment 23 of the web corners 19. The protrusion 67 extends outwardly from the side of the plunger -12 a distance approximately equal to the thickness of the carton board and forces the portion of the triangular segment 22 that overlaps the cutout 25 of the triangular segment 23 therethrough into contact with the end panel 15. Inasmuch as the glue areas 31 are on this portion, the triangular segment 22 is adhered to the end panel 15 thus rigidly holding the side panels 14 and the end panels 15 erect substantially perpendicular to the bottom panel 16. As shown, protrusions 67 in each corner positively adhere all four corners of the carton.

The lower or second portion of the forming die must positively hold the side panels 14 firmly against the plunger 12 as it erects the end panels 15 about the plunger 12 to assure proper positioning of the triangular segments 22 and 23. The movable die plates 56 that form two opposing walls of the lower or second portion of the forming die must be removed from the retracted position, as was the case during the glue application, to a forward position that will hold the side panels 14 firmly erected against the plunger 12. Referring to FIG. 15, the plunger 12 is positioned in the forming die as shown in FIG. 17 with the side panels of the carton past the glue applying heads 30. The movable die plate 56 has been relocated toward the plunger 12 and now lies coplanar below the first pair of forming plates 26 and contacts the side panels 14 of the carton. The the plate cam 62 has rotated in the direction indicated by the arrow so that the cam follower 63 is riding the recessed portion of the cam surface. The tension spring 65 has forced the cam follower 63 into the recessed portion causing a counterclockwise rotation of the U-shaped link 59. The rotation moves the upper portion of the U-shaped link to the left as viewed, thus moving the top portion of the movable die plate 56 to the left. The connecting link 61 rotates about its pivoted ends and moves the lower portion of the movable die plates 56 in toward the plunger 12 coplanar with the first pair of forming plates 26. The movable die plates 56 are now positioned to hold the side panels 14 erect against the plunger 12 so that the end panels 15 can be erected as shown in FIG. 5.

The plunger 12 continues through the second or lower portion of the forming die on into a glue setting section that holds the erected carton against the plunger 12 until the glue has hardened enough to hold the carton erect. The setting section extends from the second pair of forming plates 66 to the lower end of the forming die. The cross sectional area of the setting section conforms generally to the bottom panel 16 of the carton and is enclosed by the innermost reaches of the second pair of forming plates 66 and the movable die plates 56.

As the plunger 12 continues through the second or lower portion of the forming die, the topof the carton consisting of the overlapping side panels 18 and the top panel 17 have remained unfolded. Referring to FIG. 19, a clearance 68 between the ends of the second pair of forming plates 66, and one of the movable die plates 56 is formed by terminating the second pair of forming plates 66 on the ends nearest to the top panel 17 of the canton. As the plunger 12 pushes the carton past the second pair of forming plates 66, the overlapping side panels 13 pass through the clearance 63. It should be obvious that without the clearance 68, the overlapping side panels 18 would jam against the second pair of forming plates 66. This is clearly shown in FIGS. 17 and 18 in which the overlapping side panels 18 can be seen to extend outside of the second pair of forming plates 66.

The plunger 12 continues to travel downwardly through the forming die until the upper edge of the side panels 14 and the end panels 15 pass beyond the bottom edges of the movable die plates 56 and the second pair of forming plates 66. The end panels 15 bow slightly outwardly away from the plunger 12 and are stripped therefrom by the bottom edges of the second pair of forming plates 66 as the plunger .12 begins to move upwardly on the return stroke through the forming die. Simultaneously with the stripping action, the movable die plates 52 are moved away from the plunger 12 thus removing the pressure on the side walls 14.

In FIG. 16, the plunger 12 is moving upwardly through the forming die in the direction indicated by the arrow. The carton is erected as shown in FIG. 5. The die plate cam 62 rotating in the direction indicated by the arrow has rotated the U-shaped link 59 clockwise, as compared with FIG. 15, about the pin 53 because the cam follower 63 has reached and is riding on the raised portion of the die plate cam 62. The clockwise rotation of the U- shaped link 59, along with the rotation of the connecting link 61 relocates the movable die plates 56 away from the plunger 12. The pressure exerted on the side panels 14 of the carton by the movable die plates 56 and the plunger 12 during glue setting is removed. A recessed lip 69 located on the lowermost edge of the movable die plate 56 opposite to the top panel 17 acts as a secondary or backup stripper by preventing the carton from travelling upwardly with the plunger '12. The recessed lip 69 receives the free edge of the side panel 14 if the carton 1G is not stripped from the plunger 12 by the lowermost edges of the second pair of forming plates 66.

By way of summary, the overall operation of the vari ous components of the carton folding machine will be briefly reviewed. Carton blanks similar to those shown in FIGS. 2, 3, 4, and 5 are fed singularly onto the die table 16 by a suitable feeder (not shown) and positioned underneath the reciprocating plunger '12 between the carton positioning blocks .13. The plunger cont-acts the bottom panel 16 of the carton and pushes the carton blank downwardly through the forming die. The first pair of forming plates 26 fold the side panels 14 of the carton upwardly about the plunger 12; as it passes thereby. The cam shafts 51 and 53, being-coupled to a common drive means through a proper choice of gearing, are sequenced to automatically activate the mechanisms that rotate the valve rod 38 of the \glue applying heads 30* thus extruding glue onto predetermined areas of the web corners 19 as the plunger pushes the canton blank thereby. During the extrusion of the glue by the glue applying heads 30, the movable die plates 56 are automatically held away from the plunger 12 by mechanisms activated by the cam shafts 51 and 53. Immediately after the completion of the glue applying, the movable die plates 56 are returned to a position where they contact the side panels 14 of the carton as the carton is pushed thereby..

The plunger .12 continues the downward forming stroke through the forming die and the end panels 15 are folded upwardly about the plunger '12 by the second pair of forming plates 66. The triangular segments 22 and 23 of the web corners 19 are folded in overlapping relationship inside of the end panels 15 in such a manner that the triangular segment 22 is adhered directly to the end panel 15 through a cutout 25 in the triangular segment 23. The movable die plates 56 and the second pair of [forming plates 66 exert a pressure upon the side panels 14 and the end panels 15 of the carton for a short period that is suificient to set the glue.

Once the plunger '12 has pushed the carton completely through the forming die, the carton is stripped off and the plunger 1-2 returns upwardly to a point beyond the top of the die table 16 into a position where a second carton blank can be placed in position to be (formed during the next downward stroke. The mechanism controlling the movable die plates 56 moves the movable die plates 56 from the plunger 12 during the stripping and remain in the removed position until the second carton has received the glue applied by the glue applying heads 30.

It should be obvious to those having ordinary skill in the art that the carton passes from the carton folding machine to a series of operations that include filling, folding the top panel 17 and the overlapping side panels 18 downwardly to form the cover, and gluing the overlapping side panels 18 to the outer surfaces of the side panels 14 and the end panels 15.

The carton folding machinery described herein is uniquely simple as compared to existing carton folding machinery. The carton folding machinery performs only two folding operations that do not include any tucking of tabs into slots. The carton folding machinery applies glue during carton setup that, when related to the folding operations, forms a carton of surprising rigidity and of especially neat appearance which needs only to be filled with the proper ingredients and sealed. The car-ton folding machine has a very small number of movable parts and requires considerably less operating space than many of the existing carton folding machines.

It should be realized that many modifications and variations are possible that are still within the scope of this invention.

I claim:

1. A carton folding machine for set-ting up cartons having tfioldable Web corners modified to be adhesively bonded to side walls of the carton to maintain the carton in erected form about the bottom panel comprising:

(a) forming die,

(b) a plunger having a face conforming generally to the bottom panel of the carton,

(0) means to move the plunger through the forming die whereby the carton side walls are formed about the plunger during the movement of the plunger through the forming die,

(d) a first pair of forming plates defining opposing Walls of the forming die, each having portions curving into the forming die, said portions defining an opening conforming generally to one dimension of the face of the plunger,

(e) adhesive applying means located behind the first pair of forming plates by the carton folding machine,

(f) said adhesive applying means having portions extending into each corner of the forming die for applying adhesive to an area of each of the web corners of the carton,

(g) means cooperating with adhesive applying means to apply adhesive to predetermined areas of the web corners of the carton during passage of the carton past the extending portions of the adhesive applying means,

(11) a second pair of forming plates defining opposing Walls of the forming die perpendicular to the first pair of forming plates and located after the termination of the first pair of forming plates by the carton folding machine, each having portions curving into the forming die, said portions defining an opening conforming generally to the other dimension of the face of the plunger,

(i) a pair of movable die plates substantially coplanar below the first pair of forming plates and forming the remaining walls of the portion of the forming die having opposing walls formed by the second pair of forming plates,

(j) activating means for moving the movable die plates in a direction substantially perpendicular to the direction of the plunger travel,

(It) said activating means simultaneously moving the movable die plates to retracted positions during the application of adhesive to the carton forming an opening conforming to greater than the associated dimension of the face of the plunger whereby the natural resiliency of the carton board is employed to press the web corners against the adhesive applymg means,

(I) said activating means simultaneously moving the movable die plates to forward positions after the application of adhesive to the carton, forming an opening conforming generally to the associated dimension of the face of the plunger whereby the carton panels are adhesively bonded and held during adhesive setting in the erected position,

(In) said activating means simultaneously returning the movable die plates to retracted positions at the completion of the downward travel of the plunger through the forming die, forming an opening conforming to greater than the associated dimension of the face of the plunger whereby the pressure exerted thereon during adhesive setting is removed allowing the carton to drop free of the plunger,

(11) and means receiving and transferring completed carton to an advance position so that succeeding completed cartons can drop free of the plunger and onto cleared receiving means.

2. A carton folding machine for setting upcartons having a bottom panel, end panels and side panels foldably attached around the perimeter of the bottom panel, and web corners foldably attached to and joining the end panels to the side panels, each of said web corners equally divided into a first and a second triangular segment by a diagonal score line, said second triangular segment in each web corner having a cutout on the free edge comprising:

(a) a forming die,

(b) a plunger having a face conforming generally to the bottom panel of the carton,

(0) means to move the plunger through the forming die,

(:1) a first pair of forming plates defining opposing walls of the forming die, each having portions curving into the forming die, said portions defining an opening conforming generally to one dimension of the face of the plunger and folding the side panels of the carton substantially perpendicular to the bottom panel while folding the web corners coplanar with the side panels as the plunger pushes the carton thereby,

(e) adhesive applying means located behind the first pair of forming plates by the carton folding machine,

(1) said adhesive applying means having portions extending into each part of the forming die passed by said web corners as the carton is pushed thereby,

(g) said adhesive applying means transferring adhesive to the first triangular segments in each web corner as the carton is pushed thereby,

(h) a second pair of forming plates defining opposing side walls of the forming die perpendicular to the first pair of forming plates and located after the termination of the first pair of forming plates by the carton folding machine, each having portions curving into the forming die, said portions defining an opening conforming generally to the other dimension of the face of the plunger and folding the end panels of the carton substantially perpendicular to the bottom panel while folding the triangular segments of the web corners inside thereof with one face of the second triangular segments against the inside surfaces of the end panels and the first triangular segments against the other face of the second triangular segments as the plunger pushes the carton thereby,

(1') means carried by the plunger for forcing the portion of the first triangular segments overlapping the cutouts of the second triangular segments through said cutouts and into contact with the end panels whereby the first triangular segments are glued to the end panels thus holding the cartons erect,

(j) and means for extracting the erected cartons from the plunger.

3. A carton folding machine for setting up cartons having a bottom panel, end panels and side panels foldably attached around the perimeter of the bottom panel, and web corners foldably attached to and joining the end panels to the side panels, each of said web corners equally divided into a first and a second triangular segment by a diagonal score line, said second triangular segment in each web corner having a cutout on the free edge comprising:

(a) a forming die,

(b) a plunger having a face conforming generally to the bottom panel of the carton,

(0) means to move the plunger through the forming die,

(d) a first pair of forming plates defining opposing walls of the forming die, each having portions curving into the forming die, said portions defining an opening conforming generally to one dimension of the face of the plunger and folding the side panels of the carton substantially perpendicular to the bottom panel while folding the web corners coplanar with the side panels as the plunger pushes the carton thereby,

(e) adhesive applying means located behind the first pair of forming plates by the carton folding machine,

(f) said adhesive applying means having portions extending into each part of the forming die passed by said web corners as the carton is pushed thereby,

(g) said adhesive applying means transferring adhesive to the first triangular segments in each web corner as the carton is pushed thereby,

(h) a second pair of forming plates defining opposing side Walls of the forming dic perpendicular to the first pair of forming plates and located after the termination of the first pair of forming plates by the carton folding machine, each having portions curving into the forming die, said portions defining an opening conforming generally to the other dimension of the face of the plunger and folding the end panels of the carton substantitally perpendicular to the bottom panel While folding the triangular segments of the web corners inside thereof with one face of the second triangular segments against the inside surfaces of the end panels and the first triangular segments against the other face of the second triangular segments as the plunger pushes the carton thereby,

(1') means carried by the plunger for forcing the portion of the first triangular segments overlapping the cutouts of the second triangular segments through said cutouts and into contact with the end panels whereby the first triangular segments are glued to the end panels,

(j) an adhesive setting section formed from a portion of the forming die located by the carton folding machine after the termination of the second pair of forming plates,

(k) said adhesive setting section defining an opening conforming generally to the face of the plunger, and holding the end panels and the side panels in erected form about the plunger during the passage of the plunger thereby until the adhesive has hardened,

(l) and means for extracting the erected carton from the plunger.

4. A carton folding machine for setting up cartons having a bottom panel, end panels and side panels foldably attached around the perimeter of the bottom panel, and Web corners foldably attached to and joining the end panels to the side panels, each of said Web corners equally divided into a first and a second triangular segment by a diagonal score line, said second triangular segment in each Web corner having a cutout on the free edge comprising:

(a) a forming die having forming plates defining an opening conforming generally to the bottom panel of the carton,

(b) a plunger having a reciprocating movement positioned by the carton folding machine to pass back and forth through the forming die,

(0) said plunger cooperating with the forming plates during alternate passes through the forming die to fold the end panels and the side panels upright about the bottom panel While folding the triangular segments of the Web corners inside thereof with one face of the second triangular segments against the inside surfaces of the end panels and the first triangular segments against the other face of the second triangular segments,

(d) adhesive applying means having portions extending into the forming die,

(e) said portions applying adhesive to the first triangular segments in each Web corner during carton setup,

(f) means carried by the plunger for forcing the portion of the first triangular segments overlapping the cutouts of the second triangular segments through said cutouts and into contact with the end panels whereby the first triangular segments are glued to the end panels thus holding the cartons erect,

(g) and means for extracting the erected carton from the plunger.

References Cited in the file of this patent UNITED STATES PATENTS 2,614,466 Palmer Oct. 21, 1952 2,830,507 Hickin et a1 Apr. 15, 1958 2,846,930 Gross Aug. 12, 1958 2,997,929 Baker et al. Aug. 29, 1961 

1. A CARTON FOLDING MACHINE FOR SETTING UP CARTONS HAVING FOLDABLE WEB CORNERS MODIFIED TO BE ADHESIVELY BONDED TO SIDE WALLS OF THE CARTON TO MAINTAIN THE CARTON IN ERECTED FORM ABOUT THE BOTTOM PANEL COMPRISING: (A) FORMING DIE, (B) A PLUNGER HAVING A FACE CONFORMING GENERALLY TO THE BOTTOM PANEL OF THE CARTON, (C) MEANS TO MOVE THE PLUNGER THROUGH THE FORMING DIE WHEREBY THE CARTON SIDE WALLS ARE FORMED ABOUT THE PLUNGER DURING THE MOVEMENT OF THE PLUNGER THROUGH THE FORMING DIE, (D) A FIRST PAIR OF FORMING PLATES DEFINING OPPOSING WALLS OF THE FORMING DIE, EACH HAVING PORTIONS CURVING INTO THE FORMING DIE, SAID PORTIONS DEFINING AN OPENING CONFORMING GENERALLY TO ONE DIMENSION OF THE FACE OF THE PLUNGER, (E) ADHESIVE APPLYING MEANS LOCATED BEHIND THE FIRST PAIR OF FORMING PLATES BY THE CARTON FOLDING MACHINE, (F) SAID ADHESIVE APPLYING MEANS HAVING PORTIONS EXTENDING INTO EACH CORNER OF THE FORMING DIE FOR APPLYING ADHESIVE TO AN AREA OF EACH OF THE WEB CORNERS OF THE CARTON, (G) MEANS COOPERATING WITH ADHESIVE APPLYING MEANS TO APPLY ADHESIVE TO PREDETERMINED AREAS OF THE WEB CORNERS OF THE CARTON DURING PASSAGE OF THE CARTON PAST THE EXTENDING PORTIONS OF THE ADHESIVE APPLYING MEANS, (H) A SECOND PAIR OF FORMING PLATES DEFINING OPPOSING WALLS OF THE FORMING DIE PERPENDICULAR TO THE FIRST PAIR OF FORMING PLATES AND LOCATED AFTER THE TERMINATION OF THE FIRST PAIR OF FORMING PLATES BY THE CARTON FOLDING MACHINE, EACH HAVING PORTIONS CURVING INTO THE FORMING DIE, SAID PORTIONS DEFINING AN OPENING CONFORMING GENERALLY TO THE OTHER DIMENSION OF THE FACE OF THE PLUNGER, (I) A PAIR OF MOVABLE DIE PLATES SUBSTANTIALLY COPLANAR BELOW THE FIRST PAIR OF FORMING PLATES AND FORMING DIE REMAINING WALLS OF THE PORTION OF THE FORMING DIE HAVING OPPOSING WALLS FORMED BY THE SECOND PAIR OF FORMING PLATES, (J) ACTIVATING MEANS FOR MOVING THE MOVABLE DIE PLATES IN A DIRECTION SUBSTANTIALLY PERPENDICULAR TO THE DIRECTION OF THE PLUNGER TRAVEL, (K) SAID ACTIVATING MEANS SIMULTANEOUSLY MOVING THE MOVABLE DIE PLATES TO RETRACTED POSITIONS DURING THE APPLICATION OF ADHESIVE TO THE CARTON FORMING AN OPENING CONFORMING TO GREATER THAN THE ASSOCIATED DIMENSION OF THE FACE OF THE PLUNGER WHEREBY THE NATURAL RESILIENCY OF THE CARTON BOARD IS EMPLOYED TO PRESS THE WEB CORNERS AGAINST THE ADHESIVE APPLYING MEANS, (L) SAID ACTIVATING MEANS SIMULTANEOUSLY MOVING THE MOVABLE DIE PLATES TO FORWARD POSITIONS AFTER THE APPLICATION OF ADHESIVE TO THE CARTON, FORMING AN OPENING CONFORMING GENERALLY TO THE ASSOCIATED DIMENSION OF THE FACE OF THE PLUNGER WHEREBY THE CARTON PANELS ARE ADHESIVELY BONDED AND HELD DURING ADHESIVE SETTING IN THE ERECTED POSITION, (M) SAID ACTIVATING MEANS SIMULTANEOUSLY RETURNING THE MOVABLE DIE PLATES TO RETRACTED POSITIONS AT THE COMPLETION OF THE DOWNWARD TRAVEL OF THE PLUNGER THROUGH THE FORMING DIE, FORMING AN OPENING CONFORMING TO GREATER THAN THE ASSOCIATED DIMENSION OF THE FACE OF THE PLUNGER WHEREBY THE PRESSURE EXERTED THEREON DURING ADHESIVE SETTING IS REMOVED ALLOWING THE CARTON TO DROP FREE OF THE PLUNGER, (N) AND MEANS RECEIVING AND TRANSFERRING COMPLETED CARTON TO AN ADVANCE POSITION SO THAT SUCCEEDING COMPLETED CARTONS CAN DROP FREE OF THE PLUNGER AND ONTO CLEARED RECEIVING MEANS. 